The present invention relates to a hybrid rotor for an aircraft, an aircraft having a hybrid rotor, the use of a hybrid rotor in an aircraft and a method for flying an aircraft.
A hybrid rotor, also described as a rotor that is a hybrid, represents a combination of two different rotor types or rotor systems. Hybrid rotors are used in aircraft, for example, airplanes, in such a way that the two rotor types or rotor systems perform different tasks. For example, German Patent Document DE 10 2007 009951 B3 discloses an aircraft in which a rotating cylinder delivers the lift, while a cycloid propeller is responsible for controllability and propulsion. The rotating cylinder is also known as Flettner rotor; in it, a rotating cylinder is subjected to an incident flow, as a result of which a force is generated that is aligned transverse to the direction of the incident flow. This force is generated based on the Magnus effect, and is therefore also described as Magnus force. Activation of the propeller elements of the cycloid propeller is technically complex.
Therefore, there is a need to provide a hybrid rotor that is constructed simply and is therefore also light-weight and can be produced cost-effectively.
This is provided by a hybrid rotor, an aircraft, the use of a hybrid rotor in an aircraft and by a method according to exemplary embodiments of the present invention.
According to an exemplary embodiment of the invention, a hybrid rotor is provided for an aircraft having a Magnus rotor, a transverse flow rotor and a guide mechanism. The Magnus rotor can be propelled rotating around a Magnus rotor axis by a first propulsion mechanism and has a closed lateral surface. The transverse flow rotor is kept rotating around an axis of rotation and has a number of axially extending rotor blades, which can be propelled rotating around the axis of rotation by a second propulsion mechanism, and which are designed fixed relative to the tangential angular position. The Magnus rotor is located within the transverse flow rotor and the Magnus rotor axis extends in the direction of the axis of rotation. The guide mechanism has a housing segment partially surrounding the transverse flow rotor in the circumferential direction, whereby the housing segment has an adjustment mechanism and is designed rotatable, at least relative to the Magnus rotor axis. The housing segment can be aligned in such a way that the transverse flow rotor generates a propelling force and brings about a transverse incident flow onto the Magnus rotor in such a way, that a force is generated according to the Magnus effect, which acts as aerodynamic lift.
As a result, it is possible to generate the two required forces for an aircraft, i.e., the propulsion force and the aerodynamic lift force by using a hybrid rotor. Accordingly, the transverse flow rotor, due to its fixed rotor blades that do not change their tangential angular position when the transverse flow rotor rotates and thus always having the same alignment to the rotation center of the rotor in order to move it on a circular track, are designed as simply as possible, i.e., the transverse flow rotor is to be designed simple and contributes to minimizing the weight of the rotor. In combination with the guide mechanism, the cross flow rotor has, in addition to the function of generating the propulsion force, a second function, namely, to bring about a transverse incident flow onto the Magnus rotor in order to make an aerodynamic lift that is as large as possible available as dynamic impulse generator with the rotating Magnus rotor. Due to the adjustability of the housing segment of the guide mechanism, this provides a hybrid rotor, which generates controllable aerodynamic lift forces and propulsion forces and is therefore suitable for an aircraft.
In contrast to aircraft that are capable of taking off vertically according to prior art, for example, so-called oscillating rotor configurations such as, for example, the V-22 Osprey, the aircraft according to the invention provides a simpler mechanical solution and greater flight safety, in particular in the transition phase between cruising flight and takeoff or landing.
According to the invention, the Magnus rotor is a rotation-symmetric hollow piece that causes a deflection of an air flow due to the Magnus effect.
According to this invention, the transverse flow rotor generates a circular flow. This is a rotary air flow that is simultaneously overlaid with a translational air flow which is likewise generated by the transverse flow rotor, or also by a movement of the aircraft in the air during a flight process.
A rotary air flow and a translational air flow form a combination flow that causes a Magnus effect at a geometric body that is exposed to the combination flow. Therefore, the body is also described as Magnus body or Magnus rotor.
In a combination flow, the rotary air flow can also be generated or supported thereby, that the Magnus rotor is activated by rotating. The rotation of the Magnus body or Magnus rotor can lead to a stronger development of the Magnus effect.
The relative motion between the surface of the Magnus rotor and the combination flow having the cited transverse circulating flow or transverse flow and the circular flow are decisive for the Magnus effect.
It should be noted that a stationary Magnus rotor or Magnus body, for example, a stationary cylinder, can already bring about a Magnus effect due to the rotating transverse flow rotor and the combination flow.
For example, the Magnus rotor is designed with a constant circular cross-section (diameter) extending over the axis of rotation; the Magnus rotor thus is a cylinder or cylindrical body in the geometric sense.
For example, the Magnus rotor is designed having a (circular) diameter changing uniformly, for example, a truncated cone, extending over the axis of rotation.
For example, the Magnus rotor is designed having a (circular) diameter that increases and again decreases parabolically, i.e. in the form of a sphere, extending over the axis of rotation.
For example, the Magnus rotor can also consist of different truncated cone segments or cylinder segments.
According to a further aspect of the invention, the Magnus rotor axis extends parallel to the axis of rotation of the transverse flow rotor.
According to a further aspect of the invention, the Magnus rotor is located concentric with respect to the transverse flow rotor.
According to a further aspect of the invention, the Magnus rotor axis extends at an incline to the axis of rotation of the transverse flow rotor, whereby the Magnus rotor axis spans, for example, a plane with the axis of rotation.
According to a further aspect of the invention, the hybrid rotor has a rotor axis, whereby the Magnus rotor axis of the Magnus rotor forms the rotor axis.
According to a further aspect of the invention, the Magnus rotor, for example, a cylinder, and the transverse flow rotor rotate around the rotor axis. The term rotor axis is used in the geometric sense in this context.
According to a further aspect of the invention, the Magnus rotor is propelled by a first shaft and the transverse flow rotor by a second shaft, whereby the first and the second shaft are, for example, located concentrically, for example, inside each other.
According to a further aspect of the invention, the Magnus rotor can be actuated in the direction of rotation of the transverse flow rotor.
According to a further aspect, the Magnus rotor can be actuated counter to the direction of rotation of the transverse flow rotor, for example, to generate a targeted downforce.
According to a further aspect, the transverse flow rotor and the Magnus rotor can also be actuated in opposite directions, for example, for purposes of braking.
According to a further aspect of the invention, the force according to the Magnus effect, also called Magnus force, which is generated at the Magnus rotor, is a lifting force and/or and a propelling force.
According to a further aspect of the invention, the transverse flow rotor generates a flow that extends transverse to the Magnus rotor axis.
According to a further aspect of the invention, the transverse flow rotor, together with the guide mechanism, forms a transverse flow blower.
According to a further aspect of the invention, the transverse flow blower serves as thrust generator.
According to an exemplary embodiment of the invention, the housing segment has the shape of a circular arc on the side facing the transverse flow rotor.
According to an exemplary embodiment of the invention, the housing segment has the same cross-section shape extending over the entire length of the Magnus rotor.
According to an alternative aspect of the invention, the housing segment has different cross-section shapes extending over the length of the Magnus rotor. As a result it is possible, for example, to provide additional aerodynamic properties of the transverse flow rotor, depending on the respective position relative to an aircraft.
According to a further aspect of the invention, in cross-section (i.e., seen horizontal to the Magnus rotor axis), the housing segment has the shape of a circular arc segment.
According to a further aspect of the invention, the housing segment has adjustable profile elements on the side facing away from the transverse flow rotor, by means of which the cross-section shape on the side facing away can be changed to improve the aerodynamic properties. For example, the changes take place depending on the rotation setting.
According to a further aspect of the invention, between the lateral surface of the Magnus rotor and the rotating rotor blades, a distance is provided in radial direction that depends on the diameter of the Magnus rotor.
For example, the diameter of the Magnus rotor is just as large up to twice the size as the distance of the lateral surface to the rotor blades.
According to a further example, the relationship of the diameter of the Magnus rotor and the distance to the rotor blades is 2:1.
According to an aspect of the invention, the profile depth and the angle of approach of the rotor blades can be chosen as desired, whereby these two parameters are related to each other with respect to the effect. Furthermore, the diameter of the transverse flow rotor can be specified. The number of rotor blades in turn is related to the diameter of the transverse flow rotor and the profile depth. If these dimensions are specified, the inner diameter of the transverse flow rotor is also known, i.e., the distance of the rotor blades from the center. The diameter of the Magnus rotor, for example, a cylinder, is then given by the relationship cited above, of the distance between the rotor blades and the lateral surface of the Magnus rotor to the diameter of the Magnus rotor.
According to an exemplary embodiment of the invention, in cross-sections, the rotor blades respectively have a curved shape with a concave and a convex side, whereby the convex side faces the Magnus rotor.
According to a further aspect of the invention, at least two, preferably sixteen rotor blades are provided.
According to an exemplary embodiment of the invention, in cross-section, the rotor blades respectively have an angle of 15° to 70° to the radial direction.
According to a further aspect of the invention, in cross-section, the rotor blades respectively have an angle of 30° to the radial direction.
The term radial direction relates to a connection line between the Magnus rotor axis and the center of the cross-section of the rotor blade, and the direction in cross-section relates to the tangential direction for a curved cross-section shape.
As has been cited already, the rotor blades do not change their angle during the rotation of the transverse flow rotor.
According to a further aspect of the invention, the rotor blades extend parallel to the axis of rotation in axial direction, i.e., they have a constant distance to the axis of rotation.
According to a further aspect of the invention, the rotor blades extend inclined to the axis of rotation in the axial direction, whereby the rotor blades have an increasing or decreasing distance with respect to the axis of rotation, i.e., the rotor blades respectively extend in a plane with the axis of rotation and are inclined to the axis of rotation.
According to an exemplary embodiment of the invention, the Magnus rotor is a cylinder, and in the area of its ends it respectively has an end plate that projects over the cylinder surface. The term cylinder surface relates to the lateral surface or circumferential surface of the cylinder.
According to a further aspect of the invention, the plates are formed at the facing ends of the cylinder.
According to a further aspect of the invention, the end plates rotate with the cylinder; for example, the plates are attached directly to the cylinder.
According to an exemplary embodiment of the invention, the cylinder has a number of plates that are located between the end plates, whereby the plates have a larger diameter than the lateral surface.
According to a further aspect, the plates are provided in a Magnus rotor that has a different rotation-symmetric shape.
According to the invention, an aircraft is also provided that has a fuselage area and at least one hybrid rotor according to one of the exemplary embodiments and aspects described above. The Magnus rotor and the transverse flow rotor of the at least one hybrid rotor are retained at the fuselage area. Furthermore, a first propulsion device for rotating the Magnus rotor of the at least one hybrid rotor and a second propulsion device for rotating the transverse flow rotor of the at least one hybrid rotor are provided. The Magnus rotor axis is located horizontal to the flight direction, for example, at an angle between 30° and 150°, preferably 45° to 135°, further preferred 80° to 100°, for example, 90°.
This makes it possible to provide an aircraft in which the hybrid rotor takes on the function of propulsion and the function of lift. In other words, compared with a conventional aircraft having an airfoil and, for example, a propulsion mechanism, the hybrid rotor takes on the function of the propeller for propulsion and the function of the airfoils for the lift.
According to a further aspect, additional airfoils are present.
According to a further aspect of the invention, for controlling the aircraft, an elevator unit and a fin are provided, for example, in the posterior section of the fuselage area.
According to a further exemplary embodiment of the invention, the aircraft has a longitudinal axis, and on both sides of the longitudinal axis, at least one hybrid rotor is provided respectively according to one of the preceding exemplary embodiments and aspects.
According to a further aspect of the invention, at least two hybrid rotors are provided that are located on diametrically opposed sides of the longitudinal axis, whereby the at least two hybrid rotors are at a distance to each other and form a propulsion pair or a propulsion group.
According to a further aspect of the invention, different rpms per hybrid rotor are provided for controlling the aircraft, i.e., as a result of the different actuation of the hybrid rotors, different lift and propulsion forces can be generated on the two sides of the longitudinal axis.
According to a further exemplary embodiment of the invention, at least two hybrid rotors located at a distance in the longitudinal direction are provided according to one of the preceding exemplary embodiments and aspects.
According to a further aspect of the invention, in the longitudinal direction, at least two propulsion pairs or two propulsion groups are provided.
The invention also includes the use of a hybrid rotor according to one of the previously described exemplary embodiments and aspects in an aircraft.
According to a further aspect of the invention, the use of an aircraft having a hybrid rotor according to one of the previously cited exemplary embodiments and aspects is provided.
According to a further exemplary embodiment of the invention, a method for flying an aircraft is provided that includes the following steps.
a) Rotating a Magnus rotor around a Magnus rotor axis, whereby the Magnus rotor has a closed lateral surface for generating a force according to the Magnus effect;
b) rotating a transverse flow rotor around an axis of rotation that has a number of axially extending rotor blades, which are designed stationary relative to the tangential angle position, whereby the rotation of the transverse flow rotor generates a propelling force for the aircraft, which runs transverse to the Magnus rotor axis; whereby the Magnus rotor is located within the transverse flow rotor and the axis of rotation extends in the direction of the Magnus rotor axis; and
c) aligning a housing segment of a guide mechanism that partially surrounds the transverse flow rotor in the circumferential direction by deviating the housing segment relative to the Magnus rotor axis in such a way that due to the transverse flow rotor, a transverse flow is created at the Magnus rotor by means of which the force according to the Magnus effect is generated.
According to a further aspect of the invention, rotating the Magnus rotor generates a lifting force.
According to a further aspect of the invention, rotating the Magnus rotor also generates a propelling force, which supports the propelling force generated by the transverse flow rotor.
According to a further aspect of the invention, the two rotor types generate a force that has a lift vector and a propulsion vector.
According to a further aspect of the invention, the transverse flow of the Magnus rotor is provided in such a way that a force according to the Magnus effect is generated that acts upon the aircraft.
According to a further aspect of the invention, the force according to the Magnus effect is a propelling force and a lifting force, as has already been mentioned above.
According to a further exemplary embodiment of the invention, the rotation of the Magnus rotor and the rotation of the transverse flow rotor and the deflection of the guide mechanism can be regulated separately in such a way that different lifting forces and propelling forces can be adjusted.
The concept of control thereby includes, for example, the following aspects:
1. The rpm of the transverse flow rotor influences the speed of the air flow and thus the thrust.
2. The rpm of the Magnus rotor influences the deflection of the air flowing against it and thus on account of the Magnus effect, the lifting force as well.
3. The rotatable deflector plate influences the direction of the air flowing around and through the hybrid rotor and thus the direction of the total force (consisting of propulsion and lift).
The cited possibilities of regulation thus make rpm changes possible that influence the magnitude of the forces. The adjustment of the deflector plate influences the direction of the forces.
According to a further aspect of the invention, different directions of flight can be selected.
According to a further aspect of the invention, the guide mechanism is adjusted in such a way that a vertical lift and propulsion force is generated that makes a vertical takeoff of the aircraft possible, or a short start, i.e., a takeoff with an extremely short runway.
Let it be pointed out that the characteristics of the exemplary embodiments and the aspects of the devices also apply to embodiments of the method as well as the use of the device and vice versa. Moreover, even those characteristics can be freely combined with each other, for which this is not explicitly mentioned.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.